The characterization of DNAJC3: elucidating the function of the TPR domains
- Mutsvunguma, Lorraine Zvichapera
- Authors: Mutsvunguma, Lorraine Zvichapera
- Date: 2014
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/55874 , vital:26751
- Description: DNAJC3 is a novel member of the DNAJ family with two domains linked to co-chaperone functions, namely the tetratricopeptide repeat (TPR) and J domain. Out of the two domains, the TPR domains are the least characterized. Therefore, the aim of this study was to characterize and elucidate additional functions of DNAJC3 TPR domains through in silico, in vitro and ex vivo approaches. Through multiple sequence and structural alignment as well as electrostatic potential analysis, DNAJC3 TPR domain were found to be most similar to TPR-containing proteins with Hsp90 or Hsp70 independent functions. In vitro pull down assays illustrated that DNAJC3 TPR domains did not interact with either cytosolic Hsp90 and Hsp70 or Grp78 and Grp94 directly, however a potential indirect interaction with Grp94 and Hsp90 was observed in mammalian lysates, via pull down assays; suggesting the formation of a complex between the proteins mediated by a specific substrate. DNAJC3 TPR domains were found to bind indiscriminately to both native and heat denatured substrates in a dose dependent manner. DNAJC3 TPR domains bound to β-galactosidase with greater affinity than malate dehydrogenase (MDH), suggesting that DNAJC3 TPR domains might exhibit substrate specificity that has not been reported before. Preliminary ex vivo analysis of DNAJC3 in mammalian cells showed that induced stress conditions did not alter the cytosolic or endoplasmic reticulum (ER) localization, or levels of DNAJC3 protein, suggesting that the protein is not stress inducible. However, protein levels of DNAJC3 were dramatically reduced by Hsp90 inhibitor novobiocin at 500 μM. Transient knockdown DNAJC3 did not change the protein levels of either Grp78 or Grp94, but decreased the protein levels of Hsp70/Hsp90 organizing protein HOP. On the other hand, protein levels of DNAJC3 were increased in HOP depleted cells. In conclusion, this study was the first to experimentally demonstrate that DNAJC3 TPR domains do not interact directly with Hsp90, Hsp70, Grp78 or Grp94, and therefore DNAJC3 is unlikely to participate in traditional co-chaperone interactions with those proteins via its TPR domain. However, the J domain is known to interact with Grp78. The discovery that DNAJC3 TPR domains resemble that of TPR-containing proteins with functions independent of Hsp90 or Hsp70 suggests that DNAJC3 might link the Hsp70/Grp78 chaperone machinery to non co-chaperone related functions, which requires further analysis.
- Full Text:
- Date Issued: 2014
- Authors: Mutsvunguma, Lorraine Zvichapera
- Date: 2014
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/55874 , vital:26751
- Description: DNAJC3 is a novel member of the DNAJ family with two domains linked to co-chaperone functions, namely the tetratricopeptide repeat (TPR) and J domain. Out of the two domains, the TPR domains are the least characterized. Therefore, the aim of this study was to characterize and elucidate additional functions of DNAJC3 TPR domains through in silico, in vitro and ex vivo approaches. Through multiple sequence and structural alignment as well as electrostatic potential analysis, DNAJC3 TPR domain were found to be most similar to TPR-containing proteins with Hsp90 or Hsp70 independent functions. In vitro pull down assays illustrated that DNAJC3 TPR domains did not interact with either cytosolic Hsp90 and Hsp70 or Grp78 and Grp94 directly, however a potential indirect interaction with Grp94 and Hsp90 was observed in mammalian lysates, via pull down assays; suggesting the formation of a complex between the proteins mediated by a specific substrate. DNAJC3 TPR domains were found to bind indiscriminately to both native and heat denatured substrates in a dose dependent manner. DNAJC3 TPR domains bound to β-galactosidase with greater affinity than malate dehydrogenase (MDH), suggesting that DNAJC3 TPR domains might exhibit substrate specificity that has not been reported before. Preliminary ex vivo analysis of DNAJC3 in mammalian cells showed that induced stress conditions did not alter the cytosolic or endoplasmic reticulum (ER) localization, or levels of DNAJC3 protein, suggesting that the protein is not stress inducible. However, protein levels of DNAJC3 were dramatically reduced by Hsp90 inhibitor novobiocin at 500 μM. Transient knockdown DNAJC3 did not change the protein levels of either Grp78 or Grp94, but decreased the protein levels of Hsp70/Hsp90 organizing protein HOP. On the other hand, protein levels of DNAJC3 were increased in HOP depleted cells. In conclusion, this study was the first to experimentally demonstrate that DNAJC3 TPR domains do not interact directly with Hsp90, Hsp70, Grp78 or Grp94, and therefore DNAJC3 is unlikely to participate in traditional co-chaperone interactions with those proteins via its TPR domain. However, the J domain is known to interact with Grp78. The discovery that DNAJC3 TPR domains resemble that of TPR-containing proteins with functions independent of Hsp90 or Hsp70 suggests that DNAJC3 might link the Hsp70/Grp78 chaperone machinery to non co-chaperone related functions, which requires further analysis.
- Full Text:
- Date Issued: 2014
The development of a personal philosophy and practice of servant leadership : a grounded theory study
- Authors: Taylor, Simon Michael
- Date: 2014
- Subjects: Hilton College (Pietermaritzburg, South Africa) , Servant leadership , Grounded theory , Community and school -- South Africa -- KwaZulu-Natal , Student volunteers in social service -- South Africa -- KwaZulu-Natal , Educational leadership -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1199 , http://hdl.handle.net/10962/d1012986
- Description: The purpose of this study is to develop a substantive grounded theory explaining the development of a philosophy and the practice of leadership amongst young adults who had attended Hilton College and whom were exposed to their servant leadership development programme. The grounded theory method in this study was developed using conventions identified by Strauss and Corbin (1990) and relying upon a collection of incidents noted during interviews with former students, teachers, housemasters, headmaster and Hiltonian Society board members. In total thirty-six interviews were conducted over a period of four years in South Africa, the United Kingdom and Kenya. Using the grounded theory methodology, an understanding of the theoretical model emerged through the development of a personal philosophy and the practice of servant leadership. Related to the central phenomenon of individual leadership philosophy and practice, the causal condition of opportunity to lead, influenced how the individual philosophy and practice emerged. Strategies used by the participants to nurture their philosophy and practice of leadership were the leadership development programme, community service, feedback and reflection. The data identified the intervening conditions and conditions relating to the context of the leadership philosophy and practice. The consequences of developing a leadership philosophy and practice were related to leadership behaviour; self-esteem; growth; follower relations; empowering of others; and relationship to institutions. The theoretical model illustrated the holistic nature of an individual’s leadership philosophy and practice. In this instance, the nature of the data revealed that the individual's leadership philosophy and practice that developed amongst the participants was predominately servant leadership. The different approaches to leadership development were scrutinised with the intention of locating the grounded theory that developed in this study, within the available literature. The literature did provide some useful insights, in particular the social field theory of Bourdieu (1998), which offered a more encompassing explanation and showed much promise in providing an understanding of leadership development. Wheatley's (1999) interpretation of field theory further explained the influence of servant leadership in leadership development. Finally, the researcher developed a set of propositions and recommendations for practice and future research and discussed the value of this research.
- Full Text:
- Date Issued: 2014
- Authors: Taylor, Simon Michael
- Date: 2014
- Subjects: Hilton College (Pietermaritzburg, South Africa) , Servant leadership , Grounded theory , Community and school -- South Africa -- KwaZulu-Natal , Student volunteers in social service -- South Africa -- KwaZulu-Natal , Educational leadership -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1199 , http://hdl.handle.net/10962/d1012986
- Description: The purpose of this study is to develop a substantive grounded theory explaining the development of a philosophy and the practice of leadership amongst young adults who had attended Hilton College and whom were exposed to their servant leadership development programme. The grounded theory method in this study was developed using conventions identified by Strauss and Corbin (1990) and relying upon a collection of incidents noted during interviews with former students, teachers, housemasters, headmaster and Hiltonian Society board members. In total thirty-six interviews were conducted over a period of four years in South Africa, the United Kingdom and Kenya. Using the grounded theory methodology, an understanding of the theoretical model emerged through the development of a personal philosophy and the practice of servant leadership. Related to the central phenomenon of individual leadership philosophy and practice, the causal condition of opportunity to lead, influenced how the individual philosophy and practice emerged. Strategies used by the participants to nurture their philosophy and practice of leadership were the leadership development programme, community service, feedback and reflection. The data identified the intervening conditions and conditions relating to the context of the leadership philosophy and practice. The consequences of developing a leadership philosophy and practice were related to leadership behaviour; self-esteem; growth; follower relations; empowering of others; and relationship to institutions. The theoretical model illustrated the holistic nature of an individual’s leadership philosophy and practice. In this instance, the nature of the data revealed that the individual's leadership philosophy and practice that developed amongst the participants was predominately servant leadership. The different approaches to leadership development were scrutinised with the intention of locating the grounded theory that developed in this study, within the available literature. The literature did provide some useful insights, in particular the social field theory of Bourdieu (1998), which offered a more encompassing explanation and showed much promise in providing an understanding of leadership development. Wheatley's (1999) interpretation of field theory further explained the influence of servant leadership in leadership development. Finally, the researcher developed a set of propositions and recommendations for practice and future research and discussed the value of this research.
- Full Text:
- Date Issued: 2014
An exploratory study of the implementation of a decentralized water provision model: a case of Chris Hani District Municipality
- Dyasi, Nobuhle Marjorie Pretty
- Authors: Dyasi, Nobuhle Marjorie Pretty
- Date: 2014
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/18532 , vital:22353
- Description: It is notable that successful implementation of strategy is very important in any organization - private or public. As such it is not surprising that public sector managers are expected to implement strategies to improve organizational performance and service delivery. Consequently, strategy implementation in the public sector has become an increasingly relevant and topical issue, especially because public sector organizations exist to meet the needs of particular stakeholder groups and maximize organizational performance rather than realize profits. Despite this growing focus of public sector management literature on strategy, “there have so far been few explanations about how public sector managers develop and implement new strategic approaches” (Pablo, Reay, Dewald and Casebeer, 2007:687). This qualitative study explores the implementation of a decentralised water service provision model at Chris Hani District Municipality (CHDM) which is located in the Eastern Cape Province in South Africa. The Chris Hani District Municipality is comprised of eight local municipalities: Lukhanji, Lady Frere, Sakhisizwe, Inkwanca, Tsolwana, Inxuba Yethemba, Intsika Yethu and Engcobo. All eight municipalities were delegated to perform the water service provision function of CHDM. The research questions are: How effective was the implementation of the CHDM decentralised water services provision model? and What are the enablers of and barriers to implementing a decentralised water provision model in CHDM? The study used the McKinsey 7S framework of strategy execution to evaluate the implementation of the decentralised water services provision model in CHDM, enablers and barriers to executing this model were also identified. Purposively, a total of seven area managers were interviewed as the eighth Area Manager resigned and left the employment of CHDM during the time of the study. Data was gathered from Area Managers who are intimately involved in the daily operation of water services provision. Data was gathered through semi-structured interviews which were audio recorded, transcribed and data was coded and categorised according to the theoretical perspectives of the McKinsey 7S framework. The draft report was given to the research participants for verification or comments not only as input but also as a member check before the final report. Predominantly most of the Area Managers reflected that the implementation of the decentralised water services provision model by CHDM manifested four cornerstones: (a) reducing distance to water services, (b) delegating of water provision function and accountability, (c) improving delivery of water services, and (d) putting people first in water provision. Drivers and barriers of the implementation of the decentralized water provision strategy were identified to empower local municipalities and enhance operational efficiencies and service quality. Recommendations were made to CHDM on how the implementation of the decentralised water services provision model could be enhanced for better performance. This study will benefit CHDM on improving and strengthening the alignment of all the 7S’s elements of strategy execution to enhance the performance of the decentralised water provision model. Since no studies had been conducted previously to evaluate the implementation of a decentralised water services provision strategy at CHDM, this research is valuable to CHDM as it provides insight on the effectiveness of implementing the decentralised water provision model. Furthermore, the use of the McKinsey 7S framework to evaluate the decentralised model is valuable as it identifies and highlights the gaps where there is misalignment of the 7S’s of strategy execution. These are areas which CHDM needs to address in order to enhance or improve strategic performance.
- Full Text:
- Date Issued: 2014
- Authors: Dyasi, Nobuhle Marjorie Pretty
- Date: 2014
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/18532 , vital:22353
- Description: It is notable that successful implementation of strategy is very important in any organization - private or public. As such it is not surprising that public sector managers are expected to implement strategies to improve organizational performance and service delivery. Consequently, strategy implementation in the public sector has become an increasingly relevant and topical issue, especially because public sector organizations exist to meet the needs of particular stakeholder groups and maximize organizational performance rather than realize profits. Despite this growing focus of public sector management literature on strategy, “there have so far been few explanations about how public sector managers develop and implement new strategic approaches” (Pablo, Reay, Dewald and Casebeer, 2007:687). This qualitative study explores the implementation of a decentralised water service provision model at Chris Hani District Municipality (CHDM) which is located in the Eastern Cape Province in South Africa. The Chris Hani District Municipality is comprised of eight local municipalities: Lukhanji, Lady Frere, Sakhisizwe, Inkwanca, Tsolwana, Inxuba Yethemba, Intsika Yethu and Engcobo. All eight municipalities were delegated to perform the water service provision function of CHDM. The research questions are: How effective was the implementation of the CHDM decentralised water services provision model? and What are the enablers of and barriers to implementing a decentralised water provision model in CHDM? The study used the McKinsey 7S framework of strategy execution to evaluate the implementation of the decentralised water services provision model in CHDM, enablers and barriers to executing this model were also identified. Purposively, a total of seven area managers were interviewed as the eighth Area Manager resigned and left the employment of CHDM during the time of the study. Data was gathered from Area Managers who are intimately involved in the daily operation of water services provision. Data was gathered through semi-structured interviews which were audio recorded, transcribed and data was coded and categorised according to the theoretical perspectives of the McKinsey 7S framework. The draft report was given to the research participants for verification or comments not only as input but also as a member check before the final report. Predominantly most of the Area Managers reflected that the implementation of the decentralised water services provision model by CHDM manifested four cornerstones: (a) reducing distance to water services, (b) delegating of water provision function and accountability, (c) improving delivery of water services, and (d) putting people first in water provision. Drivers and barriers of the implementation of the decentralized water provision strategy were identified to empower local municipalities and enhance operational efficiencies and service quality. Recommendations were made to CHDM on how the implementation of the decentralised water services provision model could be enhanced for better performance. This study will benefit CHDM on improving and strengthening the alignment of all the 7S’s elements of strategy execution to enhance the performance of the decentralised water provision model. Since no studies had been conducted previously to evaluate the implementation of a decentralised water services provision strategy at CHDM, this research is valuable to CHDM as it provides insight on the effectiveness of implementing the decentralised water provision model. Furthermore, the use of the McKinsey 7S framework to evaluate the decentralised model is valuable as it identifies and highlights the gaps where there is misalignment of the 7S’s of strategy execution. These are areas which CHDM needs to address in order to enhance or improve strategic performance.
- Full Text:
- Date Issued: 2014
An investigation of the potential anti-diabetic (insulinomimetic) activity of anti-oxidant compounds derived from Sargassum heterophyllum
- Authors: Nyambe, Mutenta Nsokolo
- Date: 2014
- Subjects: Sargassum , Diabetes -- Chemotherapy , Diabetes -- Africa , Antioxidants -- Therapeutic use , Marine algae , Endemic plants -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3874 , http://hdl.handle.net/10962/d1021020
- Description: In Africa, non-communicable diseases such as diabetes mellitus have been generally neglected. This problem has worsened over the years owing to continuous threats from infectious diseases such as HIV/AIDS, tuberculosis and malaria. Despite this, statistics have shown that by 2030, the African region will have the highest proportional increase in diabetes prevalence. Over 80% of all diabetic deaths occur in developing countries probably not only due to poor equity of access to medication but also due to limited efficacy and side effects associated with the commonly available anti-diabetic agents. Therefore, this creates the desperate need for the development of new anti-diabetic agents that are more efficacious and can be sourced from within the continent. With oxidative stress as a suggested mechanism underlying the cause of diabetes mellitus and diabetic complications, the discovery of natural anti-oxidants that prevent free radical mediated damage is important for developing new treatment strategies. Marine algae have been identified as good sources for natural anti-oxidants. Unfortunately, very few studies have embarked on the discovery of marine-derived anti-oxidant compounds with potential anti-diabetic activity. In this project, we investigated the potential anti-oxidant activity of the South African endemic algae Stypopodium multipartitum, Dictyopterus ligulata, Cystophora fibriosa, Bifurcariopsis capensis, Sargassum sp. and Sargassum heterophyllum. From these studies, Sargassum heterophyllum yielded prenylated compounds, the main compound being sargahydroquinoic acid (3.6) and the carotenoid metabolite fucoxanthin (3.8), which are in part responsible for the radical scavenging activity of the crude extract. Sargahydroquinoic acid (3.6) and fucoxanthin (3.8) also exhibited significant anti-inflammatory activity. Sargaquinoic acid (3.1), sargachromenoic acid (3.9) and sarganaphthoquinoic acid (3.10) were then semi-synthesized from sargahydroquinoic acid (3.6) and their in-vitro cytotoxicity profiles evaluated using Chang Liver, HT-29, Caco-2 and 3T3-L1 cell lines prior to antidiabetic testing. From the semi-synthetic derivatives, sargachromenoic acid (3.9) exhibited the most potent anti-oxidant activity (IC₅₀ = 6.99 μg/mL). After the evaluation of antidiabetic activity using 3T3-L1 preadipocyte differentiation, sarganaphthoquinoic acid (3.10) showed the most potent insulinomimetic activity at 1.19 μM by inducing a PPARγ response similar to that of rosiglitazone at 1 μM.
- Full Text:
- Date Issued: 2014
- Authors: Nyambe, Mutenta Nsokolo
- Date: 2014
- Subjects: Sargassum , Diabetes -- Chemotherapy , Diabetes -- Africa , Antioxidants -- Therapeutic use , Marine algae , Endemic plants -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3874 , http://hdl.handle.net/10962/d1021020
- Description: In Africa, non-communicable diseases such as diabetes mellitus have been generally neglected. This problem has worsened over the years owing to continuous threats from infectious diseases such as HIV/AIDS, tuberculosis and malaria. Despite this, statistics have shown that by 2030, the African region will have the highest proportional increase in diabetes prevalence. Over 80% of all diabetic deaths occur in developing countries probably not only due to poor equity of access to medication but also due to limited efficacy and side effects associated with the commonly available anti-diabetic agents. Therefore, this creates the desperate need for the development of new anti-diabetic agents that are more efficacious and can be sourced from within the continent. With oxidative stress as a suggested mechanism underlying the cause of diabetes mellitus and diabetic complications, the discovery of natural anti-oxidants that prevent free radical mediated damage is important for developing new treatment strategies. Marine algae have been identified as good sources for natural anti-oxidants. Unfortunately, very few studies have embarked on the discovery of marine-derived anti-oxidant compounds with potential anti-diabetic activity. In this project, we investigated the potential anti-oxidant activity of the South African endemic algae Stypopodium multipartitum, Dictyopterus ligulata, Cystophora fibriosa, Bifurcariopsis capensis, Sargassum sp. and Sargassum heterophyllum. From these studies, Sargassum heterophyllum yielded prenylated compounds, the main compound being sargahydroquinoic acid (3.6) and the carotenoid metabolite fucoxanthin (3.8), which are in part responsible for the radical scavenging activity of the crude extract. Sargahydroquinoic acid (3.6) and fucoxanthin (3.8) also exhibited significant anti-inflammatory activity. Sargaquinoic acid (3.1), sargachromenoic acid (3.9) and sarganaphthoquinoic acid (3.10) were then semi-synthesized from sargahydroquinoic acid (3.6) and their in-vitro cytotoxicity profiles evaluated using Chang Liver, HT-29, Caco-2 and 3T3-L1 cell lines prior to antidiabetic testing. From the semi-synthetic derivatives, sargachromenoic acid (3.9) exhibited the most potent anti-oxidant activity (IC₅₀ = 6.99 μg/mL). After the evaluation of antidiabetic activity using 3T3-L1 preadipocyte differentiation, sarganaphthoquinoic acid (3.10) showed the most potent insulinomimetic activity at 1.19 μM by inducing a PPARγ response similar to that of rosiglitazone at 1 μM.
- Full Text:
- Date Issued: 2014
The Kansanshi Cu-Au deposit, Domes region, Zambia : geology, mineralisation and alteration characteristics in the main pit
- Authors: Chinyuku, Donald Tichaona
- Date: 2014
- Subjects: Kansanshi Mine -- Zambia , Copper mines and mining -- Zambia , Gold mines and mining -- Zambia , Gold -- Assaying -- Zambia , Geology -- Zambia , Mineralogy -- Zambia , Tillite
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5051 , http://hdl.handle.net/10962/d1011758 , Kansanshi Mine -- Zambia , Copper mines and mining -- Zambia , Gold mines and mining -- Zambia , Gold -- Assaying -- Zambia , Geology -- Zambia , Mineralogy -- Zambia , Tillite
- Description: The Kansanshi Cu-Au deposit located in the Domes region of the North West province of Zambia is characterised by structurally controlled high angle veins and associated alteration halos. The northwest trending Kansanshi antiform flanks the Solwezi syncline to the north and hosts the Kansanshi deposit and consists of tillites and metasedimentary rocks. Mineralisation is associated with Neoproterozoic Pan African deformation events experienced during the formation of the Lufilian fold belt; however recent findings confirm that structures in the form of reverse and normal faults and drag folds are critical controls on mineralisation within the deposit, Main pit in particular. Low angle faults occurring below the current pit are believed to have served as major fluid pathways during mineralisation. Age dating data from the Kansanshi deposit suggest that mineralisation took place between 512 and 503 Ma indicating that the event was associated with metamorphism. Two types of alteration are dominant within the Main pit (Kansanshi deposit) with the type and intensity of alteration being largely controlled by lithological units. Albite alteration occurs dominantly in phyllites and schists whereas dolomitisation is prevalent in calcareous units. Alteration is associated with mineralisation, and therefore is used as a condition for predicting vein or disseminated mineralisation. The high Au tenor at Kansanshi can be attributed to gold grains occurring in association with melonite (NiTe₂) and microfractured pyrite intergrown with chalcopyrite in sulphide and quartz dominated veins and veinlets. Analysis of gold grade distribution within the Main pit shows a clear concentration of the element along the major north-south trending structures like the 4800 and 5400 zones, possibly through supergene enrichment in the oxide-transition-sulphide zones. It is imperative that exploration for Kansanshi-type deposits will require geochemical and geophysical studies, understanding of the geology of an area to identify the three lithostratigraphic units (red beds, evaporites and reducing strata).
- Full Text:
- Date Issued: 2014
- Authors: Chinyuku, Donald Tichaona
- Date: 2014
- Subjects: Kansanshi Mine -- Zambia , Copper mines and mining -- Zambia , Gold mines and mining -- Zambia , Gold -- Assaying -- Zambia , Geology -- Zambia , Mineralogy -- Zambia , Tillite
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5051 , http://hdl.handle.net/10962/d1011758 , Kansanshi Mine -- Zambia , Copper mines and mining -- Zambia , Gold mines and mining -- Zambia , Gold -- Assaying -- Zambia , Geology -- Zambia , Mineralogy -- Zambia , Tillite
- Description: The Kansanshi Cu-Au deposit located in the Domes region of the North West province of Zambia is characterised by structurally controlled high angle veins and associated alteration halos. The northwest trending Kansanshi antiform flanks the Solwezi syncline to the north and hosts the Kansanshi deposit and consists of tillites and metasedimentary rocks. Mineralisation is associated with Neoproterozoic Pan African deformation events experienced during the formation of the Lufilian fold belt; however recent findings confirm that structures in the form of reverse and normal faults and drag folds are critical controls on mineralisation within the deposit, Main pit in particular. Low angle faults occurring below the current pit are believed to have served as major fluid pathways during mineralisation. Age dating data from the Kansanshi deposit suggest that mineralisation took place between 512 and 503 Ma indicating that the event was associated with metamorphism. Two types of alteration are dominant within the Main pit (Kansanshi deposit) with the type and intensity of alteration being largely controlled by lithological units. Albite alteration occurs dominantly in phyllites and schists whereas dolomitisation is prevalent in calcareous units. Alteration is associated with mineralisation, and therefore is used as a condition for predicting vein or disseminated mineralisation. The high Au tenor at Kansanshi can be attributed to gold grains occurring in association with melonite (NiTe₂) and microfractured pyrite intergrown with chalcopyrite in sulphide and quartz dominated veins and veinlets. Analysis of gold grade distribution within the Main pit shows a clear concentration of the element along the major north-south trending structures like the 4800 and 5400 zones, possibly through supergene enrichment in the oxide-transition-sulphide zones. It is imperative that exploration for Kansanshi-type deposits will require geochemical and geophysical studies, understanding of the geology of an area to identify the three lithostratigraphic units (red beds, evaporites and reducing strata).
- Full Text:
- Date Issued: 2014
The development and implementation of a mental toughness training programme for cricketers
- Authors: McInerney, Michael
- Date: 2014
- Subjects: Sports -- Psychological aspects , Athletes -- Conduct of life , Mental discipline , Achievement motivation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3234 , http://hdl.handle.net/10962/d1013155
- Description: The professional turn in sports has prompted the search for explanations beyond the physical when discussing quality of performance. Mental Toughness has been recognised as one of the most important psychological attributes in achieving performance excellence across multiple sport settings. Yet, despite this, little research has been conducted into mental toughness development. This research seeks to answer the question: What insights can the development and implementation of a mental toughness programme for a semi-professional South African cricket team provide regarding Mental Toughness development? Based on a theoretical framework of mental toughness in cricket, a programme was developed in collaboration with the Border Cricket Team and Coaches. Incorporating elements that focussed on education, environment, awareness and mental skills, the programme was implemented in both individual and group settings during the off- and pre-seasons. An analysis of the participants’ experiences identified the need for a theoretical understanding of mental toughness within teams, facilitating the design of interventions that integrate the team and the individual. Future programmes should include measures of mastery, and individually customised approaches to mental toughness enhancement that acknowledge the potential contextual and individual variation in mental toughness.
- Full Text:
- Date Issued: 2014
- Authors: McInerney, Michael
- Date: 2014
- Subjects: Sports -- Psychological aspects , Athletes -- Conduct of life , Mental discipline , Achievement motivation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3234 , http://hdl.handle.net/10962/d1013155
- Description: The professional turn in sports has prompted the search for explanations beyond the physical when discussing quality of performance. Mental Toughness has been recognised as one of the most important psychological attributes in achieving performance excellence across multiple sport settings. Yet, despite this, little research has been conducted into mental toughness development. This research seeks to answer the question: What insights can the development and implementation of a mental toughness programme for a semi-professional South African cricket team provide regarding Mental Toughness development? Based on a theoretical framework of mental toughness in cricket, a programme was developed in collaboration with the Border Cricket Team and Coaches. Incorporating elements that focussed on education, environment, awareness and mental skills, the programme was implemented in both individual and group settings during the off- and pre-seasons. An analysis of the participants’ experiences identified the need for a theoretical understanding of mental toughness within teams, facilitating the design of interventions that integrate the team and the individual. Future programmes should include measures of mastery, and individually customised approaches to mental toughness enhancement that acknowledge the potential contextual and individual variation in mental toughness.
- Full Text:
- Date Issued: 2014
Tourism and development : a case study of Mdumbi Backpackers and Transcape non-profit organisation
- Authors: Hitchcock, Kelly Alexandra
- Date: 2014
- Subjects: Mdumbi Backpackers -- South Africa -- Eastern Cape , Tourism -- South Africa -- Eastern Cape , Tourism -- South Africa -- Eastern Cape -- Planning , Backpacking -- South Africa -- Eastern Cape -- Case studies , Black people -- Employment -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape , Economic development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3377 , http://hdl.handle.net/10962/d1013143
- Description: The former Transkei region of the Eastern Cape of South Africa, in common with many of the other former Bantustans, is currently facing a developmental backlog. It is one of the poorest regions of the country and is a direct product of South Africa’s history of colonisation and geopolitical nature of apartheid in which people were forcibly located onto former tribal lands, called Bantustans. Tourism is one of the few business opportunities providing employment along the former Transkei coast. The tourism industry has been identified by many worldwide as a key strategy that can lead to economic upliftment, community development and poverty relief in the developing world. The predicament however, lies in the challenge of accepting or managing the negative consequences of tourism for the potential long term benefits offered by tourism-led development. Tourism development theory reflects development theory from traditional, top-down economic-growth based models to a more wide based approach with an emphasis on bottom-up planning, meeting of basic human need and a focus on sustainable development. Consequentially new and alternative forms of tourism have emerged and can be viewed as a response to some of the negative consequences of the mass tourism-led model of economic development. Backpacker tourism is one niche of the tourism market that is providing positive local socioeconomic benefits. This thesis is presented as a case study of Mdumbi Backpackers on the former Transkei coast. Mdumbi Backpackers is a unique example of a model of tourism that is providing meaningful benefits to the people who live in this community. By going one step further with the creation of the non-profit organisation Transcape, their involvement in the community has grown significantly, encouraging positive and sustainable development in the areas of social development, education and health. Mdumbi Backpackers goes beyond the notions of locally owned and sustainable approaches and actively encourages development by setting up community organisations and initiatives in a sustainable and equitable way. This approach to tourism-led development is well suited for the needs and objectives of the community as well preserving the natural environment. This thesis presents an exemplary example from which lessons can be learned and applied to developing tourism in a sustainable and equitable way in other rural communities.
- Full Text:
- Date Issued: 2014
- Authors: Hitchcock, Kelly Alexandra
- Date: 2014
- Subjects: Mdumbi Backpackers -- South Africa -- Eastern Cape , Tourism -- South Africa -- Eastern Cape , Tourism -- South Africa -- Eastern Cape -- Planning , Backpacking -- South Africa -- Eastern Cape -- Case studies , Black people -- Employment -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape , Economic development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3377 , http://hdl.handle.net/10962/d1013143
- Description: The former Transkei region of the Eastern Cape of South Africa, in common with many of the other former Bantustans, is currently facing a developmental backlog. It is one of the poorest regions of the country and is a direct product of South Africa’s history of colonisation and geopolitical nature of apartheid in which people were forcibly located onto former tribal lands, called Bantustans. Tourism is one of the few business opportunities providing employment along the former Transkei coast. The tourism industry has been identified by many worldwide as a key strategy that can lead to economic upliftment, community development and poverty relief in the developing world. The predicament however, lies in the challenge of accepting or managing the negative consequences of tourism for the potential long term benefits offered by tourism-led development. Tourism development theory reflects development theory from traditional, top-down economic-growth based models to a more wide based approach with an emphasis on bottom-up planning, meeting of basic human need and a focus on sustainable development. Consequentially new and alternative forms of tourism have emerged and can be viewed as a response to some of the negative consequences of the mass tourism-led model of economic development. Backpacker tourism is one niche of the tourism market that is providing positive local socioeconomic benefits. This thesis is presented as a case study of Mdumbi Backpackers on the former Transkei coast. Mdumbi Backpackers is a unique example of a model of tourism that is providing meaningful benefits to the people who live in this community. By going one step further with the creation of the non-profit organisation Transcape, their involvement in the community has grown significantly, encouraging positive and sustainable development in the areas of social development, education and health. Mdumbi Backpackers goes beyond the notions of locally owned and sustainable approaches and actively encourages development by setting up community organisations and initiatives in a sustainable and equitable way. This approach to tourism-led development is well suited for the needs and objectives of the community as well preserving the natural environment. This thesis presents an exemplary example from which lessons can be learned and applied to developing tourism in a sustainable and equitable way in other rural communities.
- Full Text:
- Date Issued: 2014
A study of spherical solutions in chameleon scalar-tensor theories
- Authors: Mohapi, Neo
- Date: 2014
- Subjects: Scalar field theory , Equivalence principle (Physics) , General relativity (Physics) , Bosons , Dark energy (Astronomy) , Galactic dynamics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5428 , http://hdl.handle.net/10962/d1013315
- Description: The equivalence principle has proven to be central to theories of gravity, with General Relativity being the simplest and most elegant theory to embody the principle. Most alternative theories of gravity struggle to satisfy the principle and still be distinct from GR. Extensions of cosmological and quantum theories question the irrefutably of the equivalence at every scale. The possibility of an equivalence principle violation at galactic scales would be an exciting prospect. In this thesis, we will carefully examine the equivalence principle through the study of chameleon scalar-tensor theories, this will include solutions for hypothetical stars known as boson stars. Such theories find varied application, especially in cosmology, where they model dark energy and inflation. The AWE hypothesis, is an instance of this. It is a nonuniversally coupled model in which violations of the equivalence principle on galactic scales may be apparent. We investigate spherically symmetric and static solutions within the framework of this theory. The constraints obtained from galactic rotation curves results in values of the couplings that show no significant violation of the equivalence principle or values consistent with a theory of dark energy
- Full Text:
- Date Issued: 2014
- Authors: Mohapi, Neo
- Date: 2014
- Subjects: Scalar field theory , Equivalence principle (Physics) , General relativity (Physics) , Bosons , Dark energy (Astronomy) , Galactic dynamics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5428 , http://hdl.handle.net/10962/d1013315
- Description: The equivalence principle has proven to be central to theories of gravity, with General Relativity being the simplest and most elegant theory to embody the principle. Most alternative theories of gravity struggle to satisfy the principle and still be distinct from GR. Extensions of cosmological and quantum theories question the irrefutably of the equivalence at every scale. The possibility of an equivalence principle violation at galactic scales would be an exciting prospect. In this thesis, we will carefully examine the equivalence principle through the study of chameleon scalar-tensor theories, this will include solutions for hypothetical stars known as boson stars. Such theories find varied application, especially in cosmology, where they model dark energy and inflation. The AWE hypothesis, is an instance of this. It is a nonuniversally coupled model in which violations of the equivalence principle on galactic scales may be apparent. We investigate spherically symmetric and static solutions within the framework of this theory. The constraints obtained from galactic rotation curves results in values of the couplings that show no significant violation of the equivalence principle or values consistent with a theory of dark energy
- Full Text:
- Date Issued: 2014
Career choices of Rhodes University academics : internal and external influences on the decision making process
- Authors: Rippon, Tamsyn
- Date: 2014
- Subjects: Rhodes University -- Vocational guidance , Vocational guidance , Career development -- South Africa -- Grahamstown , College teachers -- Job satisfaction -- South Africa -- Grahamstown , Universities and colleges -- Faculty , Qualitative research
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3229 , http://hdl.handle.net/10962/d1013074
- Description: The career choice process, which emphasises the term ‘choice’, is one which is characterised by an ever changing multi-layered progression (Ozbilgin, Kusku & Erdogmus, 2004). This is due to the choice being a result of the on-going interaction between an individual and their social and organisational contexts. It is then safe to assume that this career decision making process involves an awareness of an individual’s surrounding environment and an ability to acknowledge and understand what they regard as being important to them. In support of this understanding, this research project seeks to draw attention to the career influences of a specific group of professionals rather than researching career choices across a range of professionals within different contexts in efforts to broadly predict career choice behaviour. This study rather focuses on the factors that actively influenced the career choices of ten Rhodes University Academics across a range of disciplines and faculties and their individual career decision making processes. In drawing on “mainstream and heterodox” (Ozbilgin et al., 2004, p. 2) literature, this research aims to apply existing notions presented by past researchers to South African academics, now residing and working at Rhodes University, which is located in the small town of Grahamstown, Eastern Cape. The methods of qualitative inductive research are discussed and the results are explored within the settings and contexts unique to each individual who has been drawn to the specific University context. The purpose of the study is to therefore adopt an inductive thematic analysis approach in seeking to examine the internal and external factors that served to influence the sample of academics into their chosen discipline, their decision to become and academic and their employer of choice, in light of the increasing pressure on higher education institutions to contribute to social and economic transformation within the South Africa (Tettey, 2006).
- Full Text:
- Date Issued: 2014
- Authors: Rippon, Tamsyn
- Date: 2014
- Subjects: Rhodes University -- Vocational guidance , Vocational guidance , Career development -- South Africa -- Grahamstown , College teachers -- Job satisfaction -- South Africa -- Grahamstown , Universities and colleges -- Faculty , Qualitative research
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3229 , http://hdl.handle.net/10962/d1013074
- Description: The career choice process, which emphasises the term ‘choice’, is one which is characterised by an ever changing multi-layered progression (Ozbilgin, Kusku & Erdogmus, 2004). This is due to the choice being a result of the on-going interaction between an individual and their social and organisational contexts. It is then safe to assume that this career decision making process involves an awareness of an individual’s surrounding environment and an ability to acknowledge and understand what they regard as being important to them. In support of this understanding, this research project seeks to draw attention to the career influences of a specific group of professionals rather than researching career choices across a range of professionals within different contexts in efforts to broadly predict career choice behaviour. This study rather focuses on the factors that actively influenced the career choices of ten Rhodes University Academics across a range of disciplines and faculties and their individual career decision making processes. In drawing on “mainstream and heterodox” (Ozbilgin et al., 2004, p. 2) literature, this research aims to apply existing notions presented by past researchers to South African academics, now residing and working at Rhodes University, which is located in the small town of Grahamstown, Eastern Cape. The methods of qualitative inductive research are discussed and the results are explored within the settings and contexts unique to each individual who has been drawn to the specific University context. The purpose of the study is to therefore adopt an inductive thematic analysis approach in seeking to examine the internal and external factors that served to influence the sample of academics into their chosen discipline, their decision to become and academic and their employer of choice, in light of the increasing pressure on higher education institutions to contribute to social and economic transformation within the South Africa (Tettey, 2006).
- Full Text:
- Date Issued: 2014
(Re-)inventing our selves/ourselves : identity and community in contemporary South African short fiction cycles.
- Authors: Marais, Susan Jacqueline
- Date: 2014
- Subjects: South African fiction (English) -- History and criticism , Matlou, Joël -- Criticism and interpretation , Magona, Sindiwe -- Criticism and interpretation , Vladislavić, Ivan, 1957- -- Criticism and interpretation , Wicomb, Zoë -- Criticism and interpretation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2326 , http://hdl.handle.net/10962/d1016357
- Description: In this study I focus on a number of collections of short fiction by the South African writers Joël Matlou, Sindiwe Magona, Zoë Wicomb and Ivan Vladislavić, all of which evince certain of the characteristics of short story cycles or sequences. In other words, they display what Forrest L. Ingram describes as “a double tendency of asserting the individuality of [their] components on the one hand and of highlighting, on the other, the bonds of unity which make the many into a single whole”. The cycle form, thus defined, is characterised by a paradoxical yet productive and frequently unresolved tension between “the individuality of each of the stories and the necessities of the larger unit”, between “the one and the many”, and between cohesion and fragmentation. It is this “dynamic structure of connection and disconnection” which singularly equips the genre to represent the interrelationship of singular and collective identities, or the “coherent multiplicity of community”. Ingram, for example, asserts that “Numerous and varied connective strands draw the co-protagonists of any story cycle into a single community. … However this community may be achieved, it usually can be said to constitute the central character of a cycle”. Not unsurprisingly, then, in its dominant manifestations over much of the twentieth century the short story cycle demonstrated a marked inclination towards regionalism and the depiction of localised enclaves, and this tendency towards “place-based short story cycles” in which topographical unity is a conspicuous feature was as pronounced in South Africa as elsewhere. However, the specific collections which are my concern here increasingly employ innovative and self-reflexive narrative strategies that unsettle generic expectations and interrogate the notions of regionalism and community conventionally associated with the short story cycle. My investigation seeks to explain this shift in emphasis, and its particular significance within the South African context.
- Full Text:
- Date Issued: 2014
- Authors: Marais, Susan Jacqueline
- Date: 2014
- Subjects: South African fiction (English) -- History and criticism , Matlou, Joël -- Criticism and interpretation , Magona, Sindiwe -- Criticism and interpretation , Vladislavić, Ivan, 1957- -- Criticism and interpretation , Wicomb, Zoë -- Criticism and interpretation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2326 , http://hdl.handle.net/10962/d1016357
- Description: In this study I focus on a number of collections of short fiction by the South African writers Joël Matlou, Sindiwe Magona, Zoë Wicomb and Ivan Vladislavić, all of which evince certain of the characteristics of short story cycles or sequences. In other words, they display what Forrest L. Ingram describes as “a double tendency of asserting the individuality of [their] components on the one hand and of highlighting, on the other, the bonds of unity which make the many into a single whole”. The cycle form, thus defined, is characterised by a paradoxical yet productive and frequently unresolved tension between “the individuality of each of the stories and the necessities of the larger unit”, between “the one and the many”, and between cohesion and fragmentation. It is this “dynamic structure of connection and disconnection” which singularly equips the genre to represent the interrelationship of singular and collective identities, or the “coherent multiplicity of community”. Ingram, for example, asserts that “Numerous and varied connective strands draw the co-protagonists of any story cycle into a single community. … However this community may be achieved, it usually can be said to constitute the central character of a cycle”. Not unsurprisingly, then, in its dominant manifestations over much of the twentieth century the short story cycle demonstrated a marked inclination towards regionalism and the depiction of localised enclaves, and this tendency towards “place-based short story cycles” in which topographical unity is a conspicuous feature was as pronounced in South Africa as elsewhere. However, the specific collections which are my concern here increasingly employ innovative and self-reflexive narrative strategies that unsettle generic expectations and interrogate the notions of regionalism and community conventionally associated with the short story cycle. My investigation seeks to explain this shift in emphasis, and its particular significance within the South African context.
- Full Text:
- Date Issued: 2014
Biological control as an integrated control method in the management of aquatic weeds in an urban environmental and socio-political landscape : case study : Cape Town Metropolitan Area
- Authors: Stafford, Martha Louise
- Date: 2014
- Subjects: Aquatic weeds -- South Africa -- Cape Town , Aquatic weeds -- Biological control -- South Africa -- Cape Town , Water hyacinth -- Biological control -- South Africa -- Cape Town , Metropolitan areas -- South Africa -- Cape Town
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5874 , http://hdl.handle.net/10962/d1013015
- Description: Aquatic weeds transform and degrade the ecosystems which they invade, impacting various aspects of their surroundings ranging from the community level to disrupting important processes affecting ecosystem services. All of the major aquatic weeds of South Africa are found in the Cape Town Metropolitan Area. Landowners, whether private or public, are legally obliged to manage the listed invasive species through applying environmentally acceptable methodologies. This thesis provides an overview of the strategic management options, prevention, early detection, rapid response and eradication of new invasions, and containment and control species of established species. It discusses the different control methods available for managing aquatic weeds, namely mechanical, manual, chemical and biological, and the integration of different methods to improve their effectiveness. Although various studies have shown that biological control is the most cost–effective, environmentally-friendly and sustainable method, it is not yet fully integrated into weed management programmes in South Africa. In addition, the successes achieved in other parts of the world with the control of water hyacinth through biological control have not been repeated in the urban environment, despite the fact that South Africa has the highest number of biological control agents available for the weed. Urbanisation puts pressure on the natural environment and ecosystem functioning. Nutrient-enriched waters support aquatic weed growth and pose a challenge to the management thereof, in particular with regard to integrating biological control into management programmes. The aims of this study were to determine the reasons for the lack of integration of biological control into weed management programmes in South Africa, to determine the feasibility of integrating biological control in aquatic weed management programmes in a complex urban environmental and socio-political landscape by means of three case studies in the Cape Town Metropolitan Area, which showed that biological control is feasible in urban environments and should be considered. Two surveys were conducted to determine the reasons for the lack of integration of biological control into weed management programmes. The surveys showed that there is a gap between research and implementation as a result of poor communication, non-supporting institutional arrangements and a lack of appropriate capacity and skills at the implementation level. Recommendations were offered to address these issues.
- Full Text:
- Date Issued: 2014
- Authors: Stafford, Martha Louise
- Date: 2014
- Subjects: Aquatic weeds -- South Africa -- Cape Town , Aquatic weeds -- Biological control -- South Africa -- Cape Town , Water hyacinth -- Biological control -- South Africa -- Cape Town , Metropolitan areas -- South Africa -- Cape Town
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5874 , http://hdl.handle.net/10962/d1013015
- Description: Aquatic weeds transform and degrade the ecosystems which they invade, impacting various aspects of their surroundings ranging from the community level to disrupting important processes affecting ecosystem services. All of the major aquatic weeds of South Africa are found in the Cape Town Metropolitan Area. Landowners, whether private or public, are legally obliged to manage the listed invasive species through applying environmentally acceptable methodologies. This thesis provides an overview of the strategic management options, prevention, early detection, rapid response and eradication of new invasions, and containment and control species of established species. It discusses the different control methods available for managing aquatic weeds, namely mechanical, manual, chemical and biological, and the integration of different methods to improve their effectiveness. Although various studies have shown that biological control is the most cost–effective, environmentally-friendly and sustainable method, it is not yet fully integrated into weed management programmes in South Africa. In addition, the successes achieved in other parts of the world with the control of water hyacinth through biological control have not been repeated in the urban environment, despite the fact that South Africa has the highest number of biological control agents available for the weed. Urbanisation puts pressure on the natural environment and ecosystem functioning. Nutrient-enriched waters support aquatic weed growth and pose a challenge to the management thereof, in particular with regard to integrating biological control into management programmes. The aims of this study were to determine the reasons for the lack of integration of biological control into weed management programmes in South Africa, to determine the feasibility of integrating biological control in aquatic weed management programmes in a complex urban environmental and socio-political landscape by means of three case studies in the Cape Town Metropolitan Area, which showed that biological control is feasible in urban environments and should be considered. Two surveys were conducted to determine the reasons for the lack of integration of biological control into weed management programmes. The surveys showed that there is a gap between research and implementation as a result of poor communication, non-supporting institutional arrangements and a lack of appropriate capacity and skills at the implementation level. Recommendations were offered to address these issues.
- Full Text:
- Date Issued: 2014
Exploration for sediment-hosted copper mineralization in Kaponda Prospect, Central African Copperbelt, Democratic Republic of Congo
- Authors: Kabunda, Ghislain Mwape
- Date: 2014
- Subjects: Copper mines and mining -- Central African Copperbelt (Congo and Zambia) , Sedimentation -- Central African Copperbelt (Congo and Zambia) , Prospecting -- Central African Copperbelt (Congo and Zambia) , Geological mapping -- Central African Copperbelt (Congo and Zambia) , Geochemistry -- Central African Copperbelt (Congo and Zambia) , Induced polarization
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5061 , http://hdl.handle.net/10962/d1013129
- Description: The Kaponda Prospect represents a surface of 915.8 km² located at about 10 km south of the town of Lubumbashi and 33km NW of Kasumbalesa in the Democratic Republic of Congo (DRC). It lies within Neoproterozoic sedimentary rocks of the Katangan Supergroup in the Central African Copperbelt (CACB). In this province, copper mineralization occurs at different stratigraphic level with different associated alteration. Mineralization is of multistage origin from synsedimentary, diagenetic to post orogenic. Since the discovery of the CACB in the early 20th century, several exploration techniques have been used to delineate Cu deposits. A review and application of these methods including remote sensing, geological mapping, geochemical and geophysical surveys, and drilling, gives an insight of their effectiveness and limitation before analyzing their results from the Kaponda Prospect. The geology and structure of the Prospect is represented by a series of two NW trending disharmonic tight anticlines, locally domal, with cores occupied by either Roan Group or “Grand Conglomerat” Formation. These anticlines are separated by an open syncline made of Kundelungu rocks. Two mains direction of faults are recognized, the NW and NE trending structures. The latter direction are normal transfer faults which can serve as conduit for mineralization. They are related to the late orogenic extension of the Lufilian belt. However NE trending faults are believed to be associated to the climax of Lufilian folding or represents synsedimentary intergrowth faults. Exploration approach for sediment-hosted Cu within Kaponda Prospect, take into account the integration of all information derived from different techniques. Remote sensing is used as aid to geology. Landsat and Google earth images show lineaments that corresponds to lithostratigraphy boundary and domal anticline. Geological mapping identified reduced horizons which can potentially host mineralization, whereas analysis of structure measurements reveals the geometry of fold and direction of its axial plane and hinge. Statistical methods such as the main + 2 standard deviation, the frequency histogram and probability plot, together with experiential method are used to constrain and define Cu and Co thresholds values in soil samples. It appears that in this region, log-probability plot and histogram methods combined with spatial representation and the experience of the region, are the best practice to constrain and separate geochemical background from anomaly data. Ground and airborne magnetic, and radiometric images show specific signatures which map alteration and particularly lithostratigraphy such as “Roan” Group, “Grand Conglomerat” unit, “Nguba” cap carbonates and “Kundelungu” siliciclastic units. Analysis of faults interpreted from geophysical maps identified three major directions: E-W, NE-SW and NW-SE. The E-W faults are also interpreted as normal transfer faults such NE-SW structures, consistent with regional geological map. Although pole-dipole array of induced polarization (IP) survey was directly targeting disseminated Cu sulphide, its results suffer in responding to graphitic rocks and barren pyrite. Only relative small chargeable bodies need to be tested in drilling follow-up. A total of 15 targets have been generated through re-interpretation and integration of both geological mapping and remote sensing, geochemical and geophysical data, as well as existing drilling. Specific recommendations of follow-up works are advised for each type of target.
- Full Text:
- Date Issued: 2014
- Authors: Kabunda, Ghislain Mwape
- Date: 2014
- Subjects: Copper mines and mining -- Central African Copperbelt (Congo and Zambia) , Sedimentation -- Central African Copperbelt (Congo and Zambia) , Prospecting -- Central African Copperbelt (Congo and Zambia) , Geological mapping -- Central African Copperbelt (Congo and Zambia) , Geochemistry -- Central African Copperbelt (Congo and Zambia) , Induced polarization
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5061 , http://hdl.handle.net/10962/d1013129
- Description: The Kaponda Prospect represents a surface of 915.8 km² located at about 10 km south of the town of Lubumbashi and 33km NW of Kasumbalesa in the Democratic Republic of Congo (DRC). It lies within Neoproterozoic sedimentary rocks of the Katangan Supergroup in the Central African Copperbelt (CACB). In this province, copper mineralization occurs at different stratigraphic level with different associated alteration. Mineralization is of multistage origin from synsedimentary, diagenetic to post orogenic. Since the discovery of the CACB in the early 20th century, several exploration techniques have been used to delineate Cu deposits. A review and application of these methods including remote sensing, geological mapping, geochemical and geophysical surveys, and drilling, gives an insight of their effectiveness and limitation before analyzing their results from the Kaponda Prospect. The geology and structure of the Prospect is represented by a series of two NW trending disharmonic tight anticlines, locally domal, with cores occupied by either Roan Group or “Grand Conglomerat” Formation. These anticlines are separated by an open syncline made of Kundelungu rocks. Two mains direction of faults are recognized, the NW and NE trending structures. The latter direction are normal transfer faults which can serve as conduit for mineralization. They are related to the late orogenic extension of the Lufilian belt. However NE trending faults are believed to be associated to the climax of Lufilian folding or represents synsedimentary intergrowth faults. Exploration approach for sediment-hosted Cu within Kaponda Prospect, take into account the integration of all information derived from different techniques. Remote sensing is used as aid to geology. Landsat and Google earth images show lineaments that corresponds to lithostratigraphy boundary and domal anticline. Geological mapping identified reduced horizons which can potentially host mineralization, whereas analysis of structure measurements reveals the geometry of fold and direction of its axial plane and hinge. Statistical methods such as the main + 2 standard deviation, the frequency histogram and probability plot, together with experiential method are used to constrain and define Cu and Co thresholds values in soil samples. It appears that in this region, log-probability plot and histogram methods combined with spatial representation and the experience of the region, are the best practice to constrain and separate geochemical background from anomaly data. Ground and airborne magnetic, and radiometric images show specific signatures which map alteration and particularly lithostratigraphy such as “Roan” Group, “Grand Conglomerat” unit, “Nguba” cap carbonates and “Kundelungu” siliciclastic units. Analysis of faults interpreted from geophysical maps identified three major directions: E-W, NE-SW and NW-SE. The E-W faults are also interpreted as normal transfer faults such NE-SW structures, consistent with regional geological map. Although pole-dipole array of induced polarization (IP) survey was directly targeting disseminated Cu sulphide, its results suffer in responding to graphitic rocks and barren pyrite. Only relative small chargeable bodies need to be tested in drilling follow-up. A total of 15 targets have been generated through re-interpretation and integration of both geological mapping and remote sensing, geochemical and geophysical data, as well as existing drilling. Specific recommendations of follow-up works are advised for each type of target.
- Full Text:
- Date Issued: 2014
‘Gender’ and constructions of spousal mourning among the AmaXhosa in the Eastern Cape
- Authors: Ngqangweni, Hlonelwa
- Date: 2014
- Subjects: Widowhood -- South Africa -- Eastern Cape , Widows -- South Africa -- Eastern Cape , Xhosa (African people) -- Funeral customs and rites , Xhosa (African people) -- Psychology , Bereavement -- Psychological aspects , Mourning customs -- South Africa -- Eastern Cape , Death -- Social aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3249 , http://hdl.handle.net/10962/d1015647
- Description: Among the AmaXhosa the death of a person is marked by a tradition called ukuzila - the equivalent of the mourning process. As a sign of spousal mourning, and to show respect, the remaining spouse has to put on a marker (be visible). However, it is mostly the woman who is under obligation to show her mourner status by wearing ‘clothes of mourning’. The discriminatory nature of the practice, especially pertaining to visibility and some of the detrimental effects on the widows’ health and safety have been documented by some researchers, but the reasons for the continuity of visibility remain largely unexplored. Taking into account the dynamic nature of ‘culture’, this research explored the discourses deployed in men and women’s constructions of ukuzila specifically focusing on spousal mourning and the continuity of widows’ visibility in spite of their resistance to it. The research used postcolonial feminism drawing on postructuralism as its theoretical lens. This theoretical lens provided useful concepts such as hybridity, visibility, surveillance and power with which to examine spousal mourning and conceptualised people’s subject positions as multiple, fluid and contingent. Furthermore, the research employed thematic and discourse analysis at its methodology. Discourse analysis was employed to identify and analyse the discourses utilised in the constructions of spousal mourning. The research was conducted through focus group discussions held with younger and older urban and rural men and women, as well as interviews held with widows and widowers and key cultural informants. Concerning the question of constructions of spousal mourning for men and women, visibility of the mourner emerged as a central and contentious issue. Some participants were of the view that one could show mourning by engaging in culturally appropriate mourning behaviour, whilst others were of the view that showing one’s mourning had to be visible by publicly displaying mourning through a marker. Another group proposed mourning “by heart”, whereby the mourners’ status could either be inferred from their behaviour, whereas others maintained that behaviour was not mandatory. Various justifications for the continued visibility of widows were advanced. These justifications included showing love and respect to the deceased husband; showing respect to the ancestors; and helping to monitor their own behaviour in order to ensure that it is in line with appropriate mourning behaviour. The continued visibility of widows was also used to regulate the widows’ sexuality. Widows were coerced to put on ‘clothes of mourning’ in order to ‘protect’ them from being approached by men for a relationship during the mourning period. The regulation of the movement of widows was also managed through visibility. Widows’ movements were restricted in order to protect the community from pollution or bad luck. For example, they were not allowed to visit places of entertainment or visit other households. Key discourses identified were the familial-‘ukwenda’, respect-‘hlonipha’, and male sexual drive (MSD) discourse. The familial - ‘ukwenda’ discourse is centred on the idea that one is ‘married to the household’, which includes the nuclear family and wider extended family including ancestors. According to the respect-‘hlonipha’ discourse, respect is due to others on the basis of their age, status, and more especially their gender. Showing respect (hlonipha) necessitates the avoidance of all forms of behaviour and utterances that could be deemed disrespectful. The MSD holds a widespread view of sexuality as a biological drive that resides within each male and it was drawn on to make sense of discontinued visibility among widowers, whilst visibility of widows continued. It is argued that it is these discourses, embedded in the ‘culture’ of the AmaXhosa and upheld by the family that sustain the discriminatory nature of the practice, especially concerning the continued visibility of widows in spite of the resistance that has been voiced.
- Full Text:
- Date Issued: 2014
- Authors: Ngqangweni, Hlonelwa
- Date: 2014
- Subjects: Widowhood -- South Africa -- Eastern Cape , Widows -- South Africa -- Eastern Cape , Xhosa (African people) -- Funeral customs and rites , Xhosa (African people) -- Psychology , Bereavement -- Psychological aspects , Mourning customs -- South Africa -- Eastern Cape , Death -- Social aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3249 , http://hdl.handle.net/10962/d1015647
- Description: Among the AmaXhosa the death of a person is marked by a tradition called ukuzila - the equivalent of the mourning process. As a sign of spousal mourning, and to show respect, the remaining spouse has to put on a marker (be visible). However, it is mostly the woman who is under obligation to show her mourner status by wearing ‘clothes of mourning’. The discriminatory nature of the practice, especially pertaining to visibility and some of the detrimental effects on the widows’ health and safety have been documented by some researchers, but the reasons for the continuity of visibility remain largely unexplored. Taking into account the dynamic nature of ‘culture’, this research explored the discourses deployed in men and women’s constructions of ukuzila specifically focusing on spousal mourning and the continuity of widows’ visibility in spite of their resistance to it. The research used postcolonial feminism drawing on postructuralism as its theoretical lens. This theoretical lens provided useful concepts such as hybridity, visibility, surveillance and power with which to examine spousal mourning and conceptualised people’s subject positions as multiple, fluid and contingent. Furthermore, the research employed thematic and discourse analysis at its methodology. Discourse analysis was employed to identify and analyse the discourses utilised in the constructions of spousal mourning. The research was conducted through focus group discussions held with younger and older urban and rural men and women, as well as interviews held with widows and widowers and key cultural informants. Concerning the question of constructions of spousal mourning for men and women, visibility of the mourner emerged as a central and contentious issue. Some participants were of the view that one could show mourning by engaging in culturally appropriate mourning behaviour, whilst others were of the view that showing one’s mourning had to be visible by publicly displaying mourning through a marker. Another group proposed mourning “by heart”, whereby the mourners’ status could either be inferred from their behaviour, whereas others maintained that behaviour was not mandatory. Various justifications for the continued visibility of widows were advanced. These justifications included showing love and respect to the deceased husband; showing respect to the ancestors; and helping to monitor their own behaviour in order to ensure that it is in line with appropriate mourning behaviour. The continued visibility of widows was also used to regulate the widows’ sexuality. Widows were coerced to put on ‘clothes of mourning’ in order to ‘protect’ them from being approached by men for a relationship during the mourning period. The regulation of the movement of widows was also managed through visibility. Widows’ movements were restricted in order to protect the community from pollution or bad luck. For example, they were not allowed to visit places of entertainment or visit other households. Key discourses identified were the familial-‘ukwenda’, respect-‘hlonipha’, and male sexual drive (MSD) discourse. The familial - ‘ukwenda’ discourse is centred on the idea that one is ‘married to the household’, which includes the nuclear family and wider extended family including ancestors. According to the respect-‘hlonipha’ discourse, respect is due to others on the basis of their age, status, and more especially their gender. Showing respect (hlonipha) necessitates the avoidance of all forms of behaviour and utterances that could be deemed disrespectful. The MSD holds a widespread view of sexuality as a biological drive that resides within each male and it was drawn on to make sense of discontinued visibility among widowers, whilst visibility of widows continued. It is argued that it is these discourses, embedded in the ‘culture’ of the AmaXhosa and upheld by the family that sustain the discriminatory nature of the practice, especially concerning the continued visibility of widows in spite of the resistance that has been voiced.
- Full Text:
- Date Issued: 2014
Vice-Chancellor's 2014 Address to Graduation Ceremonies
- Authors: Badat, Saleem
- Date: 2014
- Language: English
- Type: text
- Identifier: vital:7868 , http://hdl.handle.net/10962/d1016417
- Full Text:
- Date Issued: 2014
- Authors: Badat, Saleem
- Date: 2014
- Language: English
- Type: text
- Identifier: vital:7868 , http://hdl.handle.net/10962/d1016417
- Full Text:
- Date Issued: 2014
Normative self-perceptions of journalists in Nigeria : the case of the Guardian newspaper
- Authors: Tiri, Judith
- Date: 2014
- Subjects: Guardian (Nigeria) , Nigeria -- In mass media , Nigeria -- Politics and government -- In mass media , Newspapers -- Nigeria , Journalism -- Political aspects -- Nigeria , Journalists -- Nigeria -- Psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3523
- Description: The study aims at interrogating the self - perceptions of journalists in Nigeria. The study is an attempt to answer some questions as: what contributions have journalists made to the democratization of Nigeria from 1960 to date? What role(s) did the media play during and after the transition to democracy? To what extent have the activities of politicians and the business class affected t he media’s social responsibility? What are the self-perceptions of journalists working in Nigeria’s The Guardian newspaper? The studies on normative theories of the press, Journalism Culture, and the perceived influences on journalism practice in a democra cy were adapted to answer the afore-listed questions. The works on how elite continuity and transitology models affect the perceptions of journalists in new democracies were also used to answer the questions posed. Since the field of research of the preced ing works is the West, the Nigerian experience points to issues that were not addressed in the prior studies because of the latter’s unique socio-political, historical, economic and ethno-religious structures . The data were collected and analyzed according to the QualitaQualitative paradigm, using in-depth semi-structured individual interviews with journalists working at The Guardian newspaper. The findings suggest that the journalists have made positive contributions to Nigeria’s democratization. The journalists that support this thesis claim that the self-perceptions of their role have changed from an adversarial position to a democratically-defined social responsibility role. This is because journalists ensure that government policies are implemented and the iss ues that affect the masses are reported. The findings show that in spite of the shift to democratization some challenges have remained, for example the journalists’ lives are not safe ; they collect bribes which are popularly called brown envelopes in Nigeria, write biased stories, and hold partisan relationships with the politicians and entrepreneurial elites and so on. The study acknowledges that democratization is in a continuum and that (the stakeholders or) civil society, journalists, the state and the entrepreneurial elites must contribute to deepen Nigeria’s democracy. The study suggests a self-perception theory that uses individual structures and institutions of a country to guide the stakeholders to play roles that will deepen democracy.
- Full Text:
- Date Issued: 2014
- Authors: Tiri, Judith
- Date: 2014
- Subjects: Guardian (Nigeria) , Nigeria -- In mass media , Nigeria -- Politics and government -- In mass media , Newspapers -- Nigeria , Journalism -- Political aspects -- Nigeria , Journalists -- Nigeria -- Psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3523
- Description: The study aims at interrogating the self - perceptions of journalists in Nigeria. The study is an attempt to answer some questions as: what contributions have journalists made to the democratization of Nigeria from 1960 to date? What role(s) did the media play during and after the transition to democracy? To what extent have the activities of politicians and the business class affected t he media’s social responsibility? What are the self-perceptions of journalists working in Nigeria’s The Guardian newspaper? The studies on normative theories of the press, Journalism Culture, and the perceived influences on journalism practice in a democra cy were adapted to answer the afore-listed questions. The works on how elite continuity and transitology models affect the perceptions of journalists in new democracies were also used to answer the questions posed. Since the field of research of the preced ing works is the West, the Nigerian experience points to issues that were not addressed in the prior studies because of the latter’s unique socio-political, historical, economic and ethno-religious structures . The data were collected and analyzed according to the QualitaQualitative paradigm, using in-depth semi-structured individual interviews with journalists working at The Guardian newspaper. The findings suggest that the journalists have made positive contributions to Nigeria’s democratization. The journalists that support this thesis claim that the self-perceptions of their role have changed from an adversarial position to a democratically-defined social responsibility role. This is because journalists ensure that government policies are implemented and the iss ues that affect the masses are reported. The findings show that in spite of the shift to democratization some challenges have remained, for example the journalists’ lives are not safe ; they collect bribes which are popularly called brown envelopes in Nigeria, write biased stories, and hold partisan relationships with the politicians and entrepreneurial elites and so on. The study acknowledges that democratization is in a continuum and that (the stakeholders or) civil society, journalists, the state and the entrepreneurial elites must contribute to deepen Nigeria’s democracy. The study suggests a self-perception theory that uses individual structures and institutions of a country to guide the stakeholders to play roles that will deepen democracy.
- Full Text:
- Date Issued: 2014
Bacterial degradation of waste coal
- Authors: Madikiza, Lwazikazi
- Date: 2014
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/54576 , vital:26590
- Description: As an energy source coal has one of the largest agglomerations in the world. Consequently mining of coal creates large volumes of waste in the form of low ranks coals. The complex structure of coal makes it difficult for the microorganisms to degrade and relatively few bacteria and fungi have been shown to break down coal. This study aimed to investigate bacteria not previously known to degrade coal. In this study bacteria were isolated from hydrocarbon contaminated sites and inoculated in coal medium where coal served as the only carbon source. Three strains produced a yellow – brown supernatant after 14 d of incubation at 30 °C. Bacteria generating a yellow – brown coloured supernatant were presumed to possess coal degrading capabilities and the best performing of these bacterial species was identified using 16s rDNA as Bacillus flexus. Scanning electron microscopy showed that there was a close association between the bacterium and substrate coal. The close association of bacteria to substrate suggested that these organisms were able to maximize solubilisation. FT-IR spectroscopic analysis demonstrated the addition of single bonded compounds COOH, OH, CN and CH that were absent prior to bacterial interaction. The increase in oxygen rich regions indicated degradation of the coal substrate. Elemental analysis showed that there was a decrease in carbon content from 47 % to 24 % during the 14 day incubation period. Reduction in coal carbon content was assumed to be due to bacterial utilization for metabolism and growth particularly as untreated coal substrate showed minimal loss of carbon. Analysis of the residual culture medium revealed that there was a linear increase in humic-like substance concentration for 8 d, coincident with increased coal biosolubilisation and colour change. Laccase activity was insignificant, and at 13 d enzyme activity was only 5×10-3 U/L suggesting that B. flexus may use a different mechanism to degrade coal. Residual culture medium remaining after bacterial action on the coal substrate appeared to possess plant growth promoting activity. This soluble biodegradation product with characteristics similar to humic acid-like substances was shown to impact growth of radish cotyledons. Expansion of isolated radish cotyledons was enhanced by 140% when incubated in coal biodegradation product. In conclusion, this study has yielded B. flexus and two other unidentified bacteria, isolated from polyaromatic hydrocarbon contaminated soils, and demonstrated the ability of these microorganisms to degrade waste coal. Further studies to elucidate the mechanism of coal breakdown by B. flexus, synergies with other coal degrading microorganisms, and incorporation of bacterium into Fungcoal bioprocess technology is imminent.
- Full Text:
- Date Issued: 2014
- Authors: Madikiza, Lwazikazi
- Date: 2014
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/54576 , vital:26590
- Description: As an energy source coal has one of the largest agglomerations in the world. Consequently mining of coal creates large volumes of waste in the form of low ranks coals. The complex structure of coal makes it difficult for the microorganisms to degrade and relatively few bacteria and fungi have been shown to break down coal. This study aimed to investigate bacteria not previously known to degrade coal. In this study bacteria were isolated from hydrocarbon contaminated sites and inoculated in coal medium where coal served as the only carbon source. Three strains produced a yellow – brown supernatant after 14 d of incubation at 30 °C. Bacteria generating a yellow – brown coloured supernatant were presumed to possess coal degrading capabilities and the best performing of these bacterial species was identified using 16s rDNA as Bacillus flexus. Scanning electron microscopy showed that there was a close association between the bacterium and substrate coal. The close association of bacteria to substrate suggested that these organisms were able to maximize solubilisation. FT-IR spectroscopic analysis demonstrated the addition of single bonded compounds COOH, OH, CN and CH that were absent prior to bacterial interaction. The increase in oxygen rich regions indicated degradation of the coal substrate. Elemental analysis showed that there was a decrease in carbon content from 47 % to 24 % during the 14 day incubation period. Reduction in coal carbon content was assumed to be due to bacterial utilization for metabolism and growth particularly as untreated coal substrate showed minimal loss of carbon. Analysis of the residual culture medium revealed that there was a linear increase in humic-like substance concentration for 8 d, coincident with increased coal biosolubilisation and colour change. Laccase activity was insignificant, and at 13 d enzyme activity was only 5×10-3 U/L suggesting that B. flexus may use a different mechanism to degrade coal. Residual culture medium remaining after bacterial action on the coal substrate appeared to possess plant growth promoting activity. This soluble biodegradation product with characteristics similar to humic acid-like substances was shown to impact growth of radish cotyledons. Expansion of isolated radish cotyledons was enhanced by 140% when incubated in coal biodegradation product. In conclusion, this study has yielded B. flexus and two other unidentified bacteria, isolated from polyaromatic hydrocarbon contaminated soils, and demonstrated the ability of these microorganisms to degrade waste coal. Further studies to elucidate the mechanism of coal breakdown by B. flexus, synergies with other coal degrading microorganisms, and incorporation of bacterium into Fungcoal bioprocess technology is imminent.
- Full Text:
- Date Issued: 2014
Some general convergence theorems on fixed points
- Authors: Panicker, Rekha Manoj
- Date: 2014
- Subjects: Fixed point theory , Convergence , Coincidence theory (Mathematics)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5426 , http://hdl.handle.net/10962/d1013112
- Description: In this thesis, we first obtain coincidence and common fixed point theorems for a pair of generalized non-expansive type mappings in a normed space. Then we discuss two types of convergence theorems, namely, the convergence of Mann iteration procedures and the convergence and stability of fixed points. In addition, we discuss the viscosity approximations generated by (ψ ,ϕ)-weakly contractive mappings and a sequence of non-expansive mappings and then establish Browder and Halpern type convergence theorems on Banach spaces. With regard to iteration procedures, we obtain a result on the convergence of Mann iteration for generalized non-expansive type mappings in a Banach space which satisfies Opial's condition. And, in the case of stability of fixed points, we obtain a number of stability results for the sequence of (ψ,ϕ)- weakly contractive mappings and the sequence of their corresponding fixed points in metric and 2-metric spaces. We also present a generalization of Fraser and Nadler type stability theorems in 2-metric spaces involving a sequence of metrics.
- Full Text:
- Date Issued: 2014
- Authors: Panicker, Rekha Manoj
- Date: 2014
- Subjects: Fixed point theory , Convergence , Coincidence theory (Mathematics)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5426 , http://hdl.handle.net/10962/d1013112
- Description: In this thesis, we first obtain coincidence and common fixed point theorems for a pair of generalized non-expansive type mappings in a normed space. Then we discuss two types of convergence theorems, namely, the convergence of Mann iteration procedures and the convergence and stability of fixed points. In addition, we discuss the viscosity approximations generated by (ψ ,ϕ)-weakly contractive mappings and a sequence of non-expansive mappings and then establish Browder and Halpern type convergence theorems on Banach spaces. With regard to iteration procedures, we obtain a result on the convergence of Mann iteration for generalized non-expansive type mappings in a Banach space which satisfies Opial's condition. And, in the case of stability of fixed points, we obtain a number of stability results for the sequence of (ψ,ϕ)- weakly contractive mappings and the sequence of their corresponding fixed points in metric and 2-metric spaces. We also present a generalization of Fraser and Nadler type stability theorems in 2-metric spaces involving a sequence of metrics.
- Full Text:
- Date Issued: 2014
Structural bioinformatics analysis of the Hsp40 and Hsp70 molecular chaperones from humans
- Authors: Adeyemi, Samson Adebowale
- Date: 2014
- Subjects: Structural bioinformatics , Molecular chaperones , Heat shock proteins , Protein-protein interactions , Biomolecules
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4171 , http://hdl.handle.net/10962/d1020962
- Description: HSP70 is one of the most important families of molecular chaperone that regulate the folding and transport of client proteins in an ATP dependent manner. The ATPase activity of HSP70 is stimulated through an interaction with its family of HSP40 co-chaperones. There is evidence to suggest that specific partnerships occur between the different HSP40 and HSP70 isoforms. While some of the residues involved in the interaction are known, many of the residues governing the specificity of HSP40-HSP70 partnerships are not precisely defined. It is not currently possible to predict which HSP40 and HSP70 isoforms will interact. We attempted to use bioinformatics to identify residues involved in the specificity of the interaction between the J domain from HSP40 and the ATPase domain from the HSP70 isoforms from humans. A total of 49 HSP40 and 13 HSP70 sequences from humans were retrieved and used for subsequent analyses. The HSP40 J domains and HSP70 ATPase domains were extracted using python scripts and classified according to the subcellular localization of the proteins using localization prediction programs. Motif analysis was carried out using the full length HSP40 proteins and Multiple Sequence Alignment (MSA) was performed to identify conserved residues that may contribute to the J domain – ATPase domain interactions. Phylogenetic inference of the proteins was also performed in order to study their evolutionary relationship. Homology models of the J domains and ATPase domains were generated. The corresponding models were docked using HADDOCK server in order to analyze possible putative interactions between the partner proteins using the Protein Interactions Calculator (PIC). The level of residue conservation was found to be higher in Type I and II HSP40 than in Type III J proteins. While highly conserved residues on helixes II and III could play critical roles in J domain interactions with corresponding HSP70s, conserved residues on helixes I and IV seemed to be significant in keeping the J domain in its right orientation for functional interactions with HSP70s. Our results also showed that helixes II and III formed the interaction interface for binding to HSP70 ATPase domain as well as the linker residues. Finally, data based docking procedures, such as applied in this study, could be an effective method to investigate protein-protein interactions complex of biomolecules.
- Full Text:
- Date Issued: 2014
- Authors: Adeyemi, Samson Adebowale
- Date: 2014
- Subjects: Structural bioinformatics , Molecular chaperones , Heat shock proteins , Protein-protein interactions , Biomolecules
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4171 , http://hdl.handle.net/10962/d1020962
- Description: HSP70 is one of the most important families of molecular chaperone that regulate the folding and transport of client proteins in an ATP dependent manner. The ATPase activity of HSP70 is stimulated through an interaction with its family of HSP40 co-chaperones. There is evidence to suggest that specific partnerships occur between the different HSP40 and HSP70 isoforms. While some of the residues involved in the interaction are known, many of the residues governing the specificity of HSP40-HSP70 partnerships are not precisely defined. It is not currently possible to predict which HSP40 and HSP70 isoforms will interact. We attempted to use bioinformatics to identify residues involved in the specificity of the interaction between the J domain from HSP40 and the ATPase domain from the HSP70 isoforms from humans. A total of 49 HSP40 and 13 HSP70 sequences from humans were retrieved and used for subsequent analyses. The HSP40 J domains and HSP70 ATPase domains were extracted using python scripts and classified according to the subcellular localization of the proteins using localization prediction programs. Motif analysis was carried out using the full length HSP40 proteins and Multiple Sequence Alignment (MSA) was performed to identify conserved residues that may contribute to the J domain – ATPase domain interactions. Phylogenetic inference of the proteins was also performed in order to study their evolutionary relationship. Homology models of the J domains and ATPase domains were generated. The corresponding models were docked using HADDOCK server in order to analyze possible putative interactions between the partner proteins using the Protein Interactions Calculator (PIC). The level of residue conservation was found to be higher in Type I and II HSP40 than in Type III J proteins. While highly conserved residues on helixes II and III could play critical roles in J domain interactions with corresponding HSP70s, conserved residues on helixes I and IV seemed to be significant in keeping the J domain in its right orientation for functional interactions with HSP70s. Our results also showed that helixes II and III formed the interaction interface for binding to HSP70 ATPase domain as well as the linker residues. Finally, data based docking procedures, such as applied in this study, could be an effective method to investigate protein-protein interactions complex of biomolecules.
- Full Text:
- Date Issued: 2014
Towards understanding the effects of stocking density on farmed South African abalone, Haliotis Midae
- Authors: Nicholson, Gareth Hurst
- Date: 2014
- Subjects: Haliotis midae -- South Africa , Haliotis midae fisheries -- South Africa , Abalones -- South Africa , Fish stocking -- South Africa , Abalone populations -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5371 , http://hdl.handle.net/10962/d1015646
- Description: The profitability of abalone farms is heavily influenced by their production per unit of grow-out space. With farms having physically expanded to the maximum, and with increasing production costs, one of the most realistic ways for farms to increase their production is through optimizing stocking densities. The effect of stocking density on Haliotis midae performance is undocumented and optimal stocking densities for this species have not been determined. Experiments were conducted under farm conditions to investigate the effects of four different stocking densities (16 %, 20 %, 22 % and 24 % of available surface area) on growth, production and health of three different size classes of abalone (15-35 g, 45-65 g, and 70-90 g start weight). Each treatment was replicated four times and trials ran over a period of eight months with measurements being made at four month intervals. Abalone behaviour was observed during the trials in the experimental tanks. Weight gain per abalone decreased with an increase in density for all tested size classes (5.04 ± 0.18 to 2.38 ± 0.17; 5.35 ± 0.21 to 4.62 ± 0.29; 7.97 ± 0.37 to 6.53 ± 0.28 g.abalone-1.month-1 for the 15-35, 45-65 and 70-90 g classes respectively, with an increased density of 16 to 24 %). Individual weight gain of 15-35 g abalone was similar at stocking densities of 16 % and 20 % while weight gain of 45-65 g and 70-90 g abalone decreased when density was increased above 16 %. Biomass gain (kg.basket-1.month-1) was not affected by stocking density in the 15-35 g and 45-65 g size classes (1.29 ± 0.02 and 0.97 ± 0.02 kg.basket-1.month-1 respectively). However, the biomass gained by baskets stocked with 70-90 g abalone increased with stocking density (1.08 ± 0.02 to 1.33 ± 0.02 kg.basket-1.month-1) with an increased density of 16 to 24 %) and did not appear to plateau within the tested density range (16 to 24 %). Food conversion ratio did not differ significantly between densities across all size classes. Stocking density did not have a significant effect on abalone condition factor or health indices. The proportion of abalone above the level of the feeder plate increased with density (7.26 ± 1.33 to 16.44 ± 1.33 with an increased density of 16 to 24 %). As a proportion of abalone situated in the area of the basket, the same proportions were situated on the walls above the feeder plate and on the feeder plate itself irrespective of stocking density (p > 0.05). Higher proportions of animals had restricted access to feed at higher stocking densities (p = 0.03). The amount of formulated feed available on the feeder plate did not differ between stocking densities throughout the night (p = 0.19). Individual abalone spent more time above the feeder plate at higher stocking densities (p < 0.05). The percentage of time above the feeder plate, spent on the walls of the basket and on the feeding surface was not significantly different at densities of 20 %, 22 % and 24 % (p > 0.05) but abalone stocked at 16 % spent a greater percentage of time above the feeder plate on the feeding surface (83.99 ± 6.26 %) than on the basket walls (16.01 ± 6.26 %). Stocking density did not affect the positioning of abalone within a basket during the day or at night. Different size H. midae are affected differently by increases in stocking density in terms of growth performance. Findings from this research may be implemented into farm management strategies to best suit production goals, whether in terms of biomass production or individual weight gain. The fundamental mechanisms resulting in reduced growth at higher densities are not well understood, however results from behaviour observations suggest that competition for preferred attachment space and feed availability are contributing to decreased growth rates. With knowledge of abalone behaviour at different densities, innovative tank designs may be established in order to counter the reduction in growth at higher densities.
- Full Text:
- Date Issued: 2014
- Authors: Nicholson, Gareth Hurst
- Date: 2014
- Subjects: Haliotis midae -- South Africa , Haliotis midae fisheries -- South Africa , Abalones -- South Africa , Fish stocking -- South Africa , Abalone populations -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5371 , http://hdl.handle.net/10962/d1015646
- Description: The profitability of abalone farms is heavily influenced by their production per unit of grow-out space. With farms having physically expanded to the maximum, and with increasing production costs, one of the most realistic ways for farms to increase their production is through optimizing stocking densities. The effect of stocking density on Haliotis midae performance is undocumented and optimal stocking densities for this species have not been determined. Experiments were conducted under farm conditions to investigate the effects of four different stocking densities (16 %, 20 %, 22 % and 24 % of available surface area) on growth, production and health of three different size classes of abalone (15-35 g, 45-65 g, and 70-90 g start weight). Each treatment was replicated four times and trials ran over a period of eight months with measurements being made at four month intervals. Abalone behaviour was observed during the trials in the experimental tanks. Weight gain per abalone decreased with an increase in density for all tested size classes (5.04 ± 0.18 to 2.38 ± 0.17; 5.35 ± 0.21 to 4.62 ± 0.29; 7.97 ± 0.37 to 6.53 ± 0.28 g.abalone-1.month-1 for the 15-35, 45-65 and 70-90 g classes respectively, with an increased density of 16 to 24 %). Individual weight gain of 15-35 g abalone was similar at stocking densities of 16 % and 20 % while weight gain of 45-65 g and 70-90 g abalone decreased when density was increased above 16 %. Biomass gain (kg.basket-1.month-1) was not affected by stocking density in the 15-35 g and 45-65 g size classes (1.29 ± 0.02 and 0.97 ± 0.02 kg.basket-1.month-1 respectively). However, the biomass gained by baskets stocked with 70-90 g abalone increased with stocking density (1.08 ± 0.02 to 1.33 ± 0.02 kg.basket-1.month-1) with an increased density of 16 to 24 %) and did not appear to plateau within the tested density range (16 to 24 %). Food conversion ratio did not differ significantly between densities across all size classes. Stocking density did not have a significant effect on abalone condition factor or health indices. The proportion of abalone above the level of the feeder plate increased with density (7.26 ± 1.33 to 16.44 ± 1.33 with an increased density of 16 to 24 %). As a proportion of abalone situated in the area of the basket, the same proportions were situated on the walls above the feeder plate and on the feeder plate itself irrespective of stocking density (p > 0.05). Higher proportions of animals had restricted access to feed at higher stocking densities (p = 0.03). The amount of formulated feed available on the feeder plate did not differ between stocking densities throughout the night (p = 0.19). Individual abalone spent more time above the feeder plate at higher stocking densities (p < 0.05). The percentage of time above the feeder plate, spent on the walls of the basket and on the feeding surface was not significantly different at densities of 20 %, 22 % and 24 % (p > 0.05) but abalone stocked at 16 % spent a greater percentage of time above the feeder plate on the feeding surface (83.99 ± 6.26 %) than on the basket walls (16.01 ± 6.26 %). Stocking density did not affect the positioning of abalone within a basket during the day or at night. Different size H. midae are affected differently by increases in stocking density in terms of growth performance. Findings from this research may be implemented into farm management strategies to best suit production goals, whether in terms of biomass production or individual weight gain. The fundamental mechanisms resulting in reduced growth at higher densities are not well understood, however results from behaviour observations suggest that competition for preferred attachment space and feed availability are contributing to decreased growth rates. With knowledge of abalone behaviour at different densities, innovative tank designs may be established in order to counter the reduction in growth at higher densities.
- Full Text:
- Date Issued: 2014
Formalisation, informalisation and the labour process within the minibus taxi industry in East London, South Africa
- Fobosi, Siyabulela Christopher
- Authors: Fobosi, Siyabulela Christopher
- Date: 2014
- Subjects: Taxicab industry -- South Africa -- East London , Taxicab industry -- South Africa -- East London -- Personnel management , Informal sector (Economics) -- South Africa -- East London , Economics -- Sociological aspects , Industrial relations -- South Africa -- East London
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3367 , http://hdl.handle.net/10962/d1012076 , Taxicab industry -- South Africa -- East London , Taxicab industry -- South Africa -- East London -- Personnel management , Informal sector (Economics) -- South Africa -- East London , Economics -- Sociological aspects , Industrial relations -- South Africa -- East London
- Description: This thesis focuses on the labour process within the minibus taxi industry in East London, South Africa. This industry is structurally situated within the informal sector or economy but is marked by contradictory processes of formalisation and in-formalisation. Though the taxi industry seems to straddle the formal and informal economies in South Africa, the study is conceptually framed in terms of the informal sector but in a critically-engaged fashion. The very distinction between formal and informal economies, whether in South Africa or elsewhere, is open to dispute; and, even if accepted, there are differing conceptualisations of the relationship between the ‘two’ economies. Also, the conceptual clarity of the term ‘informal economy’ has been subject to scrutiny, given the vast range of activities it is said to incorporate. While the distinction between formal and informal economies may be a useful conceptual starting-point, this thesis demonstrates that it is analytically useful to speak of degrees and forms of formalisation and in-formalisation along a continuum, rather than to dichotomize economies. The thesis therefore analyses in depth the competing and tension-riddled processes of formalisation and in-formalisation in the minibus taxi industry, and with a specific focus on the labour process.
- Full Text:
- Date Issued: 2014
- Authors: Fobosi, Siyabulela Christopher
- Date: 2014
- Subjects: Taxicab industry -- South Africa -- East London , Taxicab industry -- South Africa -- East London -- Personnel management , Informal sector (Economics) -- South Africa -- East London , Economics -- Sociological aspects , Industrial relations -- South Africa -- East London
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3367 , http://hdl.handle.net/10962/d1012076 , Taxicab industry -- South Africa -- East London , Taxicab industry -- South Africa -- East London -- Personnel management , Informal sector (Economics) -- South Africa -- East London , Economics -- Sociological aspects , Industrial relations -- South Africa -- East London
- Description: This thesis focuses on the labour process within the minibus taxi industry in East London, South Africa. This industry is structurally situated within the informal sector or economy but is marked by contradictory processes of formalisation and in-formalisation. Though the taxi industry seems to straddle the formal and informal economies in South Africa, the study is conceptually framed in terms of the informal sector but in a critically-engaged fashion. The very distinction between formal and informal economies, whether in South Africa or elsewhere, is open to dispute; and, even if accepted, there are differing conceptualisations of the relationship between the ‘two’ economies. Also, the conceptual clarity of the term ‘informal economy’ has been subject to scrutiny, given the vast range of activities it is said to incorporate. While the distinction between formal and informal economies may be a useful conceptual starting-point, this thesis demonstrates that it is analytically useful to speak of degrees and forms of formalisation and in-formalisation along a continuum, rather than to dichotomize economies. The thesis therefore analyses in depth the competing and tension-riddled processes of formalisation and in-formalisation in the minibus taxi industry, and with a specific focus on the labour process.
- Full Text:
- Date Issued: 2014